Data Transmission Method and Apparatus

ABSTRACT

A data transmission method and apparatus applied to the wireless communications field, where the method includes receiving, by a first access point (AP), cooperation configuration information from a second AP, where the cooperation configuration information of the second AP indicates basic cooperation information of the second AP to the first AP, and triggering, by the first AP based on a quantity of spatial streams allocated through cooperation, at least one cooperation station (STA) associated with the first AP to perform uplink data transmission using a quantity of spatial streams allocated by the first AP.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of International Patent ApplicationNo. PCT/CN2018/092346 filed on Jun. 22, 2018, which claims priority toChinese Patent Application No. 201710708312.1 filed on Aug. 17, 2017.The disclosures of the aforementioned applications are incorporatedherein by reference in their entireties.

TECHNICAL FIELD

The present application relates to the field of wireless communicationstechnologies, and especially, to a data transmission method andapparatus.

BACKGROUND

In a Wi-Fi technology, a system including one access point (AP) and oneor more associated stations (STAs) is generally referred to as a basicservice set (BSS). The AP is connected to the Internet, and the one ormore associated STA accesses a network through the AP.

With development of the Wi-Fi technology, on the basis that an initialprotocol supports only single-user sending, an uplink multi-user (MU)multiple-input and multiple-output (MIMO) technology is introduced intothe Institute of Electrical and Electronics Engineers (IEEE) 802.11axprotocol. Therefore, after an AP obtains a channel through contention,the AP may schedule a plurality of STAs in one BSS by sending a triggerframe such that the plurality of STAs simultaneously send, uplink datato the AP associated with the plurality of STAs using MIMO. However, inthis scenario, the plurality of STAs all need to be associated with theAP. That is, a plurality of users send data in parallel only in one BSS,and only to an AP associated with the plurality users.

However, as Wi-Fi deployment density increases, Wi-Fi coverage alsogradually increases from single-point coverage to area coverage. Whenone area is covered by a plurality of BSSs, bidirectional crossinterference exists between adjacent BSSs. Consequently, it isrelatively difficult for a plurality of users to transmit data inparallel in different BSSs. However, in two adjacent BSSs, two APscooperate with each other. This can implement beneficial effects, forexample, can improve system efficiency and reduce interference.

In other approaches, to implement parallel data transmission,cooperation is performed between two adjacent BSSs in a beamformingcooperation manner. In this manner, two adjacent APs need to pre-obtainstate information of a channel between each of the two APs and a targetSTA and state information of a channel between each of the two APs and acooperation STA, and the channel state information has a time validityperiod, for example, dozens of milliseconds. After the time validityperiod, a channel needs to be re-obtained, and consequently overheads ofobtaining channel information are relatively large.

SUMMARY

To resolve a problem of a related technology, the present applicationprovides a data transmission method and apparatus, and an objective ofthe present application is implemented using the following technicalsolutions.

According to a first aspect, a data transmission method is provided andis applied to an AP. The method includes: receiving, by a first AP,cooperation configuration information sent by a second AP, where thecooperation configuration information of the second AP is used toindicate basic cooperation information of the second AP to the first AP,and triggering, by the first AP, at least one cooperation STA associatedwith the first AP to perform uplink transmission using a quantity ofspatial streams allocated by the first AP, where a sum of the quantityof spatial streams allocated by the first AP to the at least onecooperation STA associated with the first AP and a quantity of spatialstreams allocated by the second AP to at least one cooperation STAassociated with the second AP does not exceed a smaller value of anupper limit of a quantity of received spatial streams of the first APand an upper limit of a quantity of received spatial streams of thesecond AP, or transmitting, by a first AP, downlink data to at least onecooperation STA associated with the first AP using a quantity of spatialstreams allocated by the first AP, where a sum of the quantity ofspatial streams allocated by the first AP to the at least onecooperation STA associated with the first AP and a quantity of spatialstreams allocated by the second AP to at least one cooperation STAassociated with the second AP does not exceed a smallest value of upperlimits of quantities of received spatial streams of all cooperation STAsassociated with the first AP and the second AP, where the basiccooperation information of the second AP includes at least an identifier(AID) of the at least one cooperation STA associated with the second AP,and the quantity of spatial streams allocated by the second AP to the atleast one cooperation STA associated with the second AP.

According to a second aspect, a data transmission method is provided andis applied to a STA. The method includes performing, by a cooperationSTA associated with a first AP based on a quantity of spatial streamsallocated by the first AP, uplink data transmission in parallel with atleast one cooperation STA associated with a second AP, where a sum ofthe quantity of spatial streams allocated by the first AP to at leastone cooperation STA associated with the first AP and a quantity ofspatial streams allocated by the second AP to the at least onecooperation STA associated with the second AP does not exceed a smallervalue of an upper limit of a quantity of received spatial streams of thefirst AP and an upper limit of a quantity of received spatial streams ofthe second AP, or receiving, by a cooperation STA associated with afirst AP based on a quantity of spatial streams allocated by the firstAP, downlink data sent by the first AP, where a sum of the quantity ofspatial streams allocated by the first AP to at least one cooperationSTA associated with the first AP and a quantity of spatial streamsallocated by a second AP to at least one cooperation STA associated withthe second AP does not exceed a smallest value of upper limits ofquantities of received spatial streams of all cooperation STAsassociated with the first AP and the second AP.

With reference to the second aspect, in a first possible implementationof the second aspect, performing, by a cooperation STA associated with afirst AP based on a quantity of spatial streams allocated by the firstAP, uplink data transmission in parallel with at least one cooperationSTA associated with a second AP includes receiving, by the cooperationSTA associated with the first AP, a first trigger frame sent by thefirst AP, where the first trigger frame is used to trigger the at leastone cooperation STA associated with the first AP to perform uplink datatransmission using a specified quantity of spatial streams and atransmission time length after a specified delay, and after waiting toreceive a second trigger frame sent by the second AP, performing, by thecooperation STA associated with the first AP based on a delay uploadindication of the first trigger frame, uplink data transmission inparallel with the at least one cooperation STA associated with thesecond AP, and there is a short interframe space (SIFS) time between thefirst trigger frame sent by the first AP and a second trigger frame sentby the second AP, the second trigger frame is used to trigger the atleast one cooperation STA associated with the second AP to performuplink data transmission using a specified quantity of spatial streamsand a transmission time length, and the transmission time length of theat least one cooperation STA associated with the first AP is the same asthat of the at least one cooperation STA associated with the second AP.

According to a third aspect, a data transmission apparatus is providedand is applied to a wireless AP. The apparatus includes a configurationunit configured to receive cooperation configuration information sent bya second AP, where the cooperation configuration information of thesecond AP is used to indicate basic cooperation information of thesecond AP to the first AP, a triggering unit configured to trigger atleast one cooperation STA associated with the first AP to perform uplinktransmission using a quantity of spatial streams allocated by the firstAP, where a sum of the quantity of spatial streams allocated by thefirst AP to the at least one cooperation STA associated with the firstAP and a quantity of spatial streams allocated by the second AP to atleast one cooperation STA associated with the second AP does not exceeda smaller value of an upper limit of a quantity of received spatialstreams of the first AP and an upper limit of a quantity of receivedspatial streams of the second AP, or a sending unit configured totransmit downlink data to at least one cooperation STA associated withthe first AP using a quantity of spatial streams allocated by the firstAP, where a sum of the quantity of spatial streams allocated by thefirst AP to the at least one cooperation STA associated with the firstAP and a quantity of spatial streams allocated by the second AP to atleast one cooperation STA associated with the second AP does not exceeda smallest value of upper limits of quantities of received spatialstreams of all cooperation STAs associated with the first AP and thesecond AP.

According to a fourth aspect, a data transmission apparatus is providedand is applied to a STA. The apparatus includes a sending unitconfigured to perform, based on a quantity of spatial streams allocatedby a first AP, uplink data transmission in parallel with at least onecooperation STA associated with a second AP, where a sum of the quantityof spatial streams allocated by the first AP to at least one cooperationSTA associated with the first AP and a quantity of spatial streamsallocated by the second AP to the at least one cooperation STAassociated with the second AP does not exceed a smaller value of anupper limit of a quantity of received spatial streams of the first APand an upper limit of a quantity of received spatial streams of thesecond AP, or a receiving unit configured to receive, based on aquantity of spatial streams allocated by the first AP, downlink datasent by the first AP, where a sum of the quantity of spatial streamsallocated by the first AP to at least one cooperation STA associatedwith the first AP and a quantity of spatial streams allocated by thesecond AP to the at least one cooperation STA associated with the secondAP does not exceed a smallest value of upper limits of quantities ofreceived spatial streams of all cooperation STAs associated with thefirst AP and the second AP.

The technical solutions provided in the embodiments of the presentapplication bring the following beneficial effects.

According to the data transmission method provided in the presentapplication, two APs negotiate to allocate a quantity of spatial streamsto a cooperation STA associated with the first AP and a cooperation STAassociated with the second AP. The two APs may trigger a plurality ofcooperation STAs associated with the two APs to perform uplink datatransmission in parallel, and the two APs may simultaneously performdownlink data transmission to the plurality of cooperation STAsassociated with the two APs. In this embodiment of the presentapplication, MU parallel data transmission associated with one AP isextended to MU parallel data transmission associated with two APs, and arange of MU parallel data transmission is extended. In addition, the twoAPs collaboratively trigger the plurality of cooperation STAs associatedwith the two APs to perform uplink data transmission in parallel or thetwo APs collaboratively send downlink data to the plurality ofcooperation STAs associated with the two APs at the same time, withoutrequiring the two APs to separately transmit data to the associatedcooperation STAs associated with the first AP and the second AP in atime division manner, thereby improving system transmission efficiency.

Further, when two APs cooperatively trigger, using two APs, theplurality of cooperation STAs associated with two APs to perform uplinkdata transmission in parallel or when two APs cooperativelysimultaneously send downlink data to the plurality of cooperation STAsassociated with two APs, uniqueness of AIDs of cooperation STAsassociated with different APs is ensured, and a case in which triggeringscheduling and data sending are confused is avoided when the AP triggersto schedule a cooperation STA associated with a cooperation AP, or whenthe AP sends downlink data to a cooperation STA associated with acooperation AP such that the AP can clearly and accurately transmit datato a corresponding STA, thereby improving cooperative transmissionaccuracy.

Further, after the AP receives uplink data of each cooperation STA, eachAP may return acknowledgement information in parallel to each associatedcooperation STA in a high-efficiency (HE) MU physical layer convergenceprocedure (PLCP) protocol data unit (PPDU) frame format. Alternatively,after the cooperation STA receives downlink data sent by each AP, eachcooperation STA may return acknowledgement information to eachassociated AP in parallel using a frame format of an HE trigger-based(TB) PPDU. This reduces time overheads caused by serially returning theacknowledgement information, and improves efficiency of returning theacknowledgement information.

BRIEF DESCRIPTION OF DRAWINGS

To describe some of the embodiments of the present application moreclearly, the following briefly describes some of the accompanyingdrawings describing the embodiments. A person of ordinary skill in theart may still derive other drawings from these accompanying drawingswithout creative efforts.

FIG. 1 is a schematic diagram of a network architecture according to anembodiment of the present application;

FIG. 2 is a schematic flowchart of a data transmission method accordingto an embodiment of the present application;

FIG. 3 is a schematic diagram of a frame structure of cooperationconfiguration information according to an embodiment of the presentapplication;

FIG. 4 is a schematic diagram of another frame structure of cooperationconfiguration information according to an embodiment of the presentapplication;

FIG. 5 is a schematic flowchart of a method for negotiating cooperationinformation according to an embodiment of the present application;

FIG. 6 is a schematic flowchart of another method for negotiatingcooperation information according to an embodiment of the presentapplication;

FIG. 7 is a schematic diagram of a frame structure of cooperationacknowledgement information according to an embodiment of the presentapplication;

FIG. 8 is a schematic flowchart of a triggering method according to anembodiment of the present application;

FIG. 9 is a schematic diagram of a time sequence of a triggering methodaccording to an embodiment of the present application;

FIG. 10 is a schematic flowchart of another triggering method accordingto an embodiment of the present application;

FIG. 11 is a schematic diagram of a time sequence of another triggeringmethod according to an embodiment of the present application;

FIG. 12 is a schematic flowchart of another triggering method accordingto an embodiment of the present application;

FIG. 13 is a schematic diagram of a time sequence of another triggeringmethod according to an embodiment of the present application;

FIG. 14 is a schematic diagram of a frame structure of an HE MU PPDUaccording to an embodiment of the present application;

FIG. 15 is a schematic flowchart of a time sequence of an uplink datatransmission method according to an embodiment of the presentapplication;

FIG. 16 is a schematic flowchart of a time sequence of a downlink datatransmission method according to an embodiment of the presentapplication;

FIG. 17 is a schematic flowchart of another downlink data transmissionmethod according to an embodiment of the present application;

FIG. 18 is a schematic flowchart of a time sequence of another downlinkdata transmission method according to an embodiment of the presentapplication;

FIG. 19 is a schematic structural diagram of an apparatus according toan embodiment of the present application;

FIG. 20 is a schematic structural diagram of an apparatus according toan embodiment of the present application;

FIG. 21 is a schematic structural diagram of an AP apparatus accordingto an embodiment of the present application; and

FIG. 22 is a schematic structural diagram of a STA apparatus accordingto an embodiment of the present application.

DESCRIPTION OF EMBODIMENTS

To enable a person skilled in the art to better understand the technicalsolutions in the embodiments of the present application, and enable theforegoing objectives, procedures, features, and advantages of theembodiments of the present application to be clearer, the followingfurther describes the technical solutions in the embodiments of thepresent application with reference to the accompanying drawings in theembodiments of the present application. The described embodiments aresome but not all of the embodiments of the present application. Allother embodiments obtained by a person of ordinary skill in the artaccording to the embodiments of the present application without creativeefforts shall fall within the protection scope of the presentapplication.

The following further describes the technical solutions and proceduresin the embodiments of the present application in detail with referenceto the accompanying drawings.

FIG. 1 shows a specific application scenario of an embodiment of thepresent application. FIG. 1 includes two APs. Cooperation STAsassociated with a first AP are a STA 11 and a STA 12, and cooperationSTAs associated with a second AP are a STA 21 and a STA 22. The two APstrigger, by negotiating cooperation configuration information, at leastone cooperation STA associated with the two APs to perform uplink datatransmission in parallel using a specified quantity of spatial streams.Certainly, in another example, there may be more APs and othercooperation STAs, and this is not shown in FIG. 1.

Embodiment 1

This embodiment provides a data transmission method.

FIG. 2 is a flowchart of a data transmission method according to anembodiment of the present application. The method may include thefollowing steps.

Step S201: A first AP receives cooperation configuration informationsent by a second AP, where the cooperation configuration information ofthe second AP is used to indicate basic cooperation information of thesecond AP to the first AP.

Further, if the first AP needs to negotiate with the second AP totrigger cooperation STAs to perform uplink data transmission inparallel, before the second AP sends the cooperation configurationinformation to the first AP, the second AP may allocate, based on aquantity of spatial streams that need to be sent by a cooperation STAassociated with the second AP, information such as a quantity of spatialstreams, a modulation and coding scheme (MCS), and a transmission timelength to the cooperation STA associated with the second AP. If thefirst AP needs to negotiate with the second AP to transmit downlink datato a STA, before the second AP sends the cooperation configurationinformation to the first AP, the second AP may determine informationsuch as a quantity of cooperation STAs involved in downlink datatransmission, a quantity of spatial streams sent by the second AP in adownlink manner, an MCS, and a transmission time length based on anupper limit of a quantity of received spatial streams of a cooperationSTA associated with the second AP and a quantity of spatial streams usedby the second AP to perform downlink transmission. After obtaining achannel usage right through channel contention, the second AP adds theforegoing information to the cooperation configuration information, andsends the cooperation configuration information to the first AP. Whenthe first AP and the second AP collaboratively trigger the cooperationSTAs to perform uplink data transmission in parallel, the cooperationconfiguration information herein includes parameters such as a quantityof cooperation STAs associated with the second AP, an AID of thecooperation STA associated with the second AP, a quantity of spatialstreams allocated by the second AP to the cooperation STA, the MCS, andthe transmission time length. When the first AP and the second AP needto collaboratively perform downlink data transmission, the cooperationconfiguration information herein includes parameters such as a quantityof cooperation STAs associated with the second AP, an AID of thecooperation STA associated with the second AP, a quantity of spatialstreams sent by the second AP to the associated cooperation STA, theMCS, and the transmission time length. A quantity of spatial streams isa quantity of spatial streams that can be transmitted in parallel in aspatial (antenna) dimension, and an upper limit of a quantity ofreceived spatial streams is a maximum quantity of spatial streams thatcan be received by an AP or a STA.

A frame structure of the cooperation configuration information may beshown in FIG. 3. The cooperation configuration information carries atleast necessary information used for cooperation. A receive end address(RA) field is a media access control (MAC) address of a cooperation AP,a transmit end address (TA) field is a MAC address of an AP that sendsthe cooperation configuration information, a cooperation STA fieldincludes two subfields, a STA identifier (ID) subfield and an SSallocation subfield. The STA ID is an AID of a cooperation STAassociated with an AP that sends the cooperation configurationinformation, and the SS allocation is information about a quantity ofspatial streams allocated by the AP that sends the cooperationconfiguration information and allocated to the cooperation STAassociated with the AP. This is shown in a solid line field in FIG. 3.Optionally, in some embodiments, when cooperation APs need tosimultaneously or separately trigger cooperation STAs respectivelyassociated with the cooperation APs to perform uplink data transmissionin parallel, or when cooperation APs need to simultaneously send, in adownlink manner, downlink data to cooperation STAs respectivelyassociated with the cooperation APs, the frame structure of thecooperation configuration information further needs to include atransmission time length (i.e., PPDU length) field. This is shown in adashed line field in FIG. 3.

Certainly, the frame structure may also be another structure. Forexample, as shown in FIG. 4, an RA field is a MAC address of acooperation AP, a TA field is a MAC address of an AP that sends thecooperation configuration information, a STA ID list field is a list ofAIDs of cooperation STAs associated with the AP that sends thecooperation configuration information, and an SS allocation subfield isinformation about quantities of spatial streams of cooperation STAscorresponding to a sequence in a STA IDs list. The foregoing fields arenecessary information for cooperation in the cooperation configurationinformation, and are shown as solid line parts in FIG. 4. Optionally, insome embodiments, when cooperation APs need to simultaneously orseparately trigger cooperation STAs respectively associated with thecooperation APs to perform uplink data transmission in parallel, or whencooperation APs need to simultaneously send, in a downlink manner,downlink data to cooperation STAs respectively associated with thecooperation APs, the frame structure of the cooperation configurationinformation further needs to include a transmission time length (i.e.,PPDU length) field. This is shown in a solid line field in FIG. 4.

Further, in the frame structure of the cooperation configurationinformation sent by the second AP, the RA field is a MAC address of thefirst AP, the TA field is a MAC address of the second AP, the STA ID isinformation about the AID of the cooperation STA associated with thesecond AP, and the SS allocation is information about the quantity ofspatial streams allocated by the second AP to the cooperation STAassociated with the second AP.

Step S202: The first AP triggers, using a quantity of spatial streamsallocated by the first AP to at least one cooperation STA associatedwith the first AP, the at least one cooperation STA associated with thefirst AP to perform uplink data transmission.

Alternatively, the first AP transmits, using a quantity of spatialstreams allocated by the first AP to at least one cooperation STAassociated with the first AP, downlink data to the at least onecooperation STA associated with the first AP.

Further, when the first AP needs to negotiate with the second AP totrigger cooperation STAs to perform uplink data transmission, after thefirst AP receives the cooperation configuration information sent by thesecond AP, under a principle of ensuring that a sum of the quantity ofspatial streams allocated by the first AP to the cooperation STAassociated with the first AP and the quantity of spatial streamsallocated by the second AP to the cooperation STA associated with thesecond AP does not exceed a smaller value in an upper limit of aquantity of received spatial streams of the first AP and an upper limitof a quantity of received spatial streams of the second AP, based on theAID that is of the cooperation STA associated with the second AP andthat is indicated in the cooperation configuration information of thesecond AP, and the quantity that is of spatial streams allocated by thesecond AP to the associated cooperation STA and that is indicated in thecooperation configuration information of the second AP, the first APallocates a quantity of useable spatial streams to the cooperation STAassociated with the first AP, or the first AP allocates a quantity ofuseable spatial streams to the cooperation STA associated with the firstAP and the cooperation STA associated with the second AP.

The first AP may send, in a broadcast manner, trigger information to thecooperation STA associated with the first AP in order to trigger thecooperation STA associated with the first AP to perform uplinktransmission using the quantity of spatial streams allocated by thefirst AP and the transmission time length.

Optionally, the first AP may alternatively send, in a broadcast manner,trigger information to the cooperation STA associated with the first APand the cooperation STA associated with the second AP in order totrigger the cooperation STA associated with the first AP and thecooperation STA associated with the second AP to separately performuplink transmission using a specified quantity of spatial streams in thetrigger information.

Further, when APs need to cooperate with each other to perform downlinkdata transmission, after the first AP receives the cooperationconfiguration information sent by the second AP, under a principle ofensuring that a sum of the quantity of spatial streams of the at leastone cooperation STA associated with the first AP and the quantity ofspatial streams allocated by the second AP to the at least onecooperation STA associated with the second AP does not exceed a smallestvalue in upper limits of quantities of received spatial streams of allcooperation STAs associated with the first AP and the second AP, basedon the quantity of spatial streams that is indicated in the cooperationconfiguration information of the second AP and that is allocated by thesecond AP to the cooperation STA associated with the second AP, thefirst AP allocates a quantity of useable spatial streams to thecooperation STA associated with the first AP, or the first AP allocatesa quantity of useable spatial streams to the cooperation STA associatedwith the first AP and the cooperation STA associated with the second AP.

Embodiment 2

this embodiment provides a method for negotiating the cooperationconfiguration information between the first AP and the second AP.

Referring to FIG. 5, the method may include the following steps.

Step S501: The first AP receives cooperation configuration informationsent by the second AP, where the cooperation configuration informationof the second AP is used to indicate basic cooperation information ofthe second AP to the first AP.

Step S501 is the same as step S201, and is not described again herein.

Step S502: The first AP allocates a quantity of remaining spatialstreams to at least one cooperation STA associated with the first AP.

Further, after the first AP receives the cooperation configurationinformation sent by the second AP, the first AP preferably considersmeeting the quantity of spatial streams allocated by the second AP tothe cooperation STA associated with the second AP.

Optionally, if the first AP needs to negotiate with the second AP totrigger the cooperation STA to perform uplink data transmission, and aquantity of spatial streams allocated by the second AP to thecooperation STA associated with the second AP does not exceed an upperlimit of a quantity of received spatial streams of the first AP, or whenthe AP needs to collaboratively perform downlink data transmission, anda quantity of spatial streams allocated by the second AP to thecooperation STA associated with the second AP does not exceed an upperlimit of a quantity of received spatial streams of the cooperation STAassociated with the first AP, the first AP allocates, based on aquantity of spatial streams that are allocated by the second AP to thecooperation STA associated with the second AP and that are carried incooperation configuration information of the second AP, the quantity ofremaining spatial streams to the cooperation STA associated with thefirst AP, where the quantity of remaining spatial streams herein is aquantity of remaining spatial streams that may be allocated to thecooperation STA associated with the first AP after the second APallocates the quantity of spatial streams to the cooperation STAassociated with the second AP.

Optionally, if the first AP needs to negotiate with the second AP totrigger the cooperation STA to perform uplink data transmission, and thequantity of spatial streams allocated by the second AP to thecooperation STA associated with the second AP exceeds an upper limit ofa quantity of received spatial streams of the first AP, or when the APneeds to collaboratively perform downlink data transmission, and thequantity of spatial streams allocated by the second AP to thecooperation STA associated with the second AP exceeds an upper limit ofa quantity of received spatial streams of the cooperation STA associatedwith the first AP, the first AP sets a quantity of associatedcooperation STAs of the first AP that can perform data transmission tozero, and does not allocate a quantity of spatial streams to anycooperation STA associated with the first AP.

Step S503: The first AP does not return cooperation acknowledgementinformation to the second AP.

After receiving the cooperation configuration information sent by thesecond AP, the first AP preferably considers meeting a cooperationrequirement and the cooperation configuration information of the secondAP. Therefore, in this negotiation, only one-way negotiation is requiredto complete the allocation of the quantity of spatial streams of thecooperation STA associated with the first AP and the second AP.

Embodiment 3

This embodiment provides another method for negotiating cooperationconfiguration information between the first AP and the second AP.

Referring to FIG. 6, the method may further include the following steps.

Step S601: The first AP receives cooperation configuration informationsent by the second AP, where the cooperation configuration informationof the second AP is used to indicate basic cooperation information ofthe second AP to the first AP.

Step S601 is the same as step S201, and is not described again herein.

Step S602: The first AP separately allocates the quantity of spatialstreams to the at least one cooperation STA associated with the first APand the at least one cooperation STA associated with the second AP.

Further, after receiving the cooperation configuration information sentby the second AP, the first AP may preferably consider allocating thequantity of spatial streams to the cooperation STA associated with thefirst AP, or may preferably meet the quantity of spatial streamsallocated by the second AP to the cooperation STA associated with thesecond AP, or may comprehensively consider the quantity of spatialstreams allocated by the first AP and the second AP to the cooperationSTAs respectively associated with the first AP and the second AP.

Optionally, the first AP may preferably allocate the quantity of spatialstreams to the cooperation STA associated with the first AP.

If the first AP needs to negotiate with the second AP to trigger thecooperation STA to perform uplink data transmission, and a totalquantity of spatial streams allocated by the second AP to thecooperation STA associated with the second AP does not exceed an upperlimit of a quantity of received spatial streams of the first AP, or whenthe AP needs to collaboratively perform downlink data transmission, anda quantity of spatial streams allocated by the second AP to thecooperation STA associated with the second AP does not exceed an upperlimit of a quantity of received spatial streams of the cooperation STAassociated with the first AP, the first AP preferably allocates thequantity of spatial streams to the cooperation STA associated with thefirst AP, and then reallocates, based on the cooperation configurationinformation of the second AP, a quantity of remaining available spatialstreams to the cooperation STA associated with the second AP. If whenthe AP needs to collaboratively trigger the STA to perform uplink datatransmission, and a total quantity of spatial streams allocated by thesecond AP to the cooperation STA associated with the second AP exceedsan upper limit of a quantity of received spatial streams of the firstAP, or when the AP needs to collaboratively perform downlink datatransmission, and a quantity of spatial streams allocated by the secondAP to the cooperation STA associated with the second AP exceeds an upperlimit of a quantity of received spatial streams of the cooperation STAassociated with the first AP, the first AP allocates a quantity of allavailable spatial streams to the cooperation STA associated with thefirst AP, and does not allocate the quantity of spatial streams to thecooperation STA associated with the second AP.

Optionally, the first AP may further preferably meet the quantity ofspatial streams allocated by the second AP to the cooperation STAassociated with the second AP.

If the first AP needs to negotiate with the second AP to trigger thecooperation STA to perform uplink data transmission, and a totalquantity of spatial streams allocated by the second AP to thecooperation STA associated with the second AP does not exceed an upperlimit of a quantity of received spatial streams of the first AP, or ifwhen the AP needs to collaboratively perform downlink data transmission,and a total quantity of spatial streams allocated by the second AP tothe cooperation STA associated with the second AP does not exceed anupper limit of a quantity of received spatial streams of the cooperationSTA associated with the first AP, the first AP preferably meets, basedon the cooperation configuration information of the second AP, thequantity of spatial streams allocated by the cooperation STA associatedwith the second AP, and allocates a quantity of remaining availablespatial streams to the cooperation STA associated with the first AP. Ifwhen the AP needs to collaboratively trigger the STA to perform uplinkdata transmission, and a total quantity of spatial streams allocated bythe second AP to the cooperation STA associated with the second APexceeds an upper limit of a quantity of received spatial streams of thefirst AP, or when the AP needs to collaboratively perform downlink datatransmission, and a quantity of spatial streams allocated by the secondAP to the cooperation STA associated with the second AP exceeds an upperlimit of a quantity of received spatial streams of the cooperation STAassociated with the first AP, the first AP sets, to zero, a quantity ofassociated cooperation STA that may be scheduled by the first AP, anddoes not allocate the quantity of spatial streams to any cooperation STAassociated with the first AP.

Optionally, the first AP may further comprehensively consider thequantity of spatial streams allocated by the first AP and the second APto the cooperation STAs respectively associated with the first AP andthe second AP. Herein, a quantity of spatial streams allocated to eachspecific cooperation STA and a method for allocating the quantity ofspatial streams are not limited. For example, the quantity of spatialstreams allocated to each specific cooperation STA and the method forallocating the quantity of spatial streams may be determined based on anemergency degree of required-to-be-transmitted data of each cooperationSTA, a time length for waiting uplink transmission, or a quantity ofspatial streams actively sent by each cooperation STA to each AP, or maybe determined based on a scheduling capability of each AP or anotheralgorithm. However, when the first AP needs to negotiate with the secondAP to trigger the cooperation STA to perform uplink data transmission, asum of a quantity of spatial streams allocated by the cooperation STAassociated with the first AP and the quantity of spatial streamsallocated by the cooperation STA associated with the second AP do notexceed a smallest value of the upper limit of the quantity of receivedspatial streams of the first AP and the upper limit of the quantity ofreceived spatial streams of the second AP. When the AP needs tocollaboratively perform downlink data transmission, a sum of thequantity of spatial streams allocated by the first AP to the at leastone cooperation STA associated with the first AP and the quantity ofspatial streams allocated by the second AP to the at least onecooperation STA associated with the second AP does not exceed a smallestvalue of upper limits of quantities of received spatial streams of allcooperation STAs associated with the first AP and the second AP.

Step S603: The first AP returns cooperation acknowledgement informationto the second AP, where the cooperation acknowledgement informationincludes at least the basic cooperation information of the first AP.

The basic cooperation information of the second AP includes AID of theat least one cooperation STA associated with the second AP, and thequantity of spatial streams allocated by the second AP to the at leastone cooperation STA associated with the second AP, and the transmissiontime length.

Optionally, when the first AP preferably meets the quantity of spatialstreams allocated by the cooperation STA associated with the second AP,the cooperation configuration information of the second AP does not needto be modified. The first AP adds the AID of the cooperation STAassociated with the first AP and the information such as the quantity ofspatial streams allocated by the first AP to the cooperation STAassociated with the first AP, the MCS, and the transmission time lengthto the cooperation acknowledgement information of the first AP, andreturns the cooperation acknowledgement information to the second APafter obtaining the channel usage right using channel contention.

Herein, a frame structure of the cooperation acknowledgement informationmay be the same as the frame structure of the cooperation configurationinformation. Details are not described herein again. Informationincluded in a specific field is different: An RA field is set to a MACaddress of the second AP, a TA field is set to a MAC address of thefirst AP, a STA AID in a cooperate STA is an AID of the cooperation STAassociated with the first AP, and an SS allocation is information aboutthe quantity of spatial streams allocated by the first AP to thecooperation STA associated with the first AP. Certainly, the framestructure of the cooperation acknowledgement information may further beanother frame structure. Optionally, as shown in FIG. 7, the framestructure of the cooperation acknowledgement information may be furtherthe same as a frame structure of a trigger frame such that the first APand the second AP complete setting of trigger information when the firstAP and the second AP subsequently jointly trigger and schedule theassociated cooperation STAs respectively associated with the first APand the second AP. The difference is that in a frame control field inthe frame structure of the cooperation acknowledgement information,setting of a type field and a subtype subfield need to be separated fromthe trigger frame. Further, a user information field (User Info)includes parameters such as an AID, a quantity of spatial streams, andan MCS of at least one cooperation STA associated with the first AP.

Optionally, when the first AP preferably allocates the quantity ofspatial streams to the cooperation STA associated with the first AP, inthe cooperation configuration information of the second AP, informationabout a quantity of spatial streams that may be allocated to thecooperation STA associated with the second AP changes. The second APadds, to the cooperation acknowledgement information, the basiccooperation information of the second AP and the basic cooperationinformation of the first AP that have been modified after reallocation,and returns the cooperation acknowledgement information to the second APafter obtaining the channel use right using channel contention.

Herein, a frame structure of the cooperation acknowledgement informationmay be the same as the frame structure of the cooperation configurationinformation. Details are not described herein again. Informationincluded in a specific field is different: an RA field is set to a MACaddress of the second AP, a TA field is set to a MAC address of thefirst AP, and a cooperative STA includes not only the AID and theinformation about the quantity of spatial stream of the cooperation STAassociated with the first AP, but also an AID of at least onecooperation STA associated with the second AP and a quantity of spatialstreams of at least one cooperation STA associated with the modifiedsecond AP after allocation. Optionally, the frame structure of thecooperation acknowledgement information is already provided in theforegoing first optional manner. Details are not described herein again.Further, the user information field includes parameters such as the AID,the quantity of spatial streams, and the MCS of the at least onecooperation STA associated with the first AP, and further includesparameters such as the AID, the quantity of spatial streams, and the MCSof the at least one cooperation STA associated with the second AP.

Therefore, the cooperation acknowledgement information returned by thefirst AP to the second AP herein may include one of the following cases:when the first AP does not modify the quantity of spatial streamsallocated to the at least one cooperation STA associated with the secondAP, the basic cooperation information of the first AP, or when the firstAP reallocates and modifies the quantity of spatial streams of at leastone cooperation STA associated with the second AP, the basic cooperationinformation of the first AP and the reallocated basic cooperationinformation of the second AP.

Herein, after two-way interaction and negotiation between the first APand the second AP, the first AP and the second AP not only clearlyunderstand the basic cooperation information of the first AP and thesecond AP, but also clearly understand the basic cooperation informationof the first AP and the second AP each other.

In this embodiment, the second AP sends the cooperation configurationinformation that carries the basic cooperation information of the secondAP to the first AP, and the first AP returns the cooperationacknowledgement information that carries at least the basic cooperationinformation of the first AP to the second AP such that the first AP andthe second AP are interactively negotiated in a two-way manner, andsubsequently, two APs cooperate to trigger each cooperation STA toperform parallel uplink data transmission or two APs cooperate toperform downlink data transmission to each cooperation STA.

Embodiment 4

This embodiment provides a process in which an AP triggers a pluralityof users to perform uplink data transmission in parallel.

In another embodiment of the present application, after the first AP andthe second AP negotiate to determine the cooperation configurationinformation, a schematic flowchart of triggering, by the first AP andthe second AP, scheduling each cooperation STA to perform uplinktransmission is shown in FIG. 8. A schematic diagram of a time sequenceis shown in FIG. 9. The method may include the following steps.

Step S801: The first AP sends a first trigger frame to a cooperation STAassociated with the first AP, where the first trigger frame is used totrigger at least one cooperation STA associated with the first AP toperform uplink data transmission using a specified quantity of spatialstreams and a specified transmission time length after a specifieddelay.

Further, after the first AP performs pre-negotiation with the second APto determine the cooperation configuration information, the first APsends the first trigger frame in a broadcast manner. In this embodimentscenario, the cooperation configuration information needs to include atransmission time length (i.e., PPDU length) such that the first AP andthe second AP separately trigger respective associated cooperation STAsto perform uplink data transmission in parallel.

Herein, the first trigger frame includes an AID, a quantity of spatialstreams, and a transmission time length that are of the cooperation STAassociated with the first AP and that are determined by negotiation, andfurther includes a delay upload indication. The first trigger frame isused to trigger the at least one cooperation STA associated with thefirst AP to perform uplink data transmission using a specified quantityof spatial streams and a specified transmission time length after aspecified delay.

Optionally, the delay upload indication in the first trigger frame maybe set on a reserved bit of a common information field in the triggerframe, and a location at which the reserved bit is located is shown inTable 1. For example, when the reserved bit in the common informationfield is set to 1, a triggered cooperation STA needs to delay uploading.When the reserved bit in the common information field is set to 0, atriggered cooperation STA does not need to delay uploading.

TABLE 1 low-density parity-check AP HE signal Trigger (LDPC) transmitfield A dependent extra (TX) Packet Spatial (HE-SIG-A) common Symbolpower extension reuse Doppler reserved Reserved info Bits: 1 6 3 16 1 91 Variable

Optionally, as shown in Table 2, the delay upload indication in thefirst trigger frame may be further set in a reserved bit of a userinformation field in the trigger frame. For example, when the reservedbit in the user information field is set to 1, a triggered cooperationSTA needs to delay uploading. When the reserved bit in the userinformation field is set to 0, a triggered cooperation STA does not needto delay uploading.

TABLE 2 Target Received Signal Resource Strength Trigger unit (RU)Coding SS Indicator dependent AID 12 allocation type MCS DCM allocation(RSSI) Reserved user Bits: 12 8 1 4 1 6 7 1 Variable

Step S802: The second AP sends a second trigger frame, where the secondtrigger frame is used to trigger the cooperation STA associated with thesecond AP to perform uplink data transmission using a specified quantityof spatial streams and a specified transmission time length.

Further, the second AP sends the second trigger frame in a broadcastmanner. There is a SIFS time between the second trigger frame sent bythe second AP and the first trigger frame sent by the first AP. Thesecond trigger frame includes an AID, a quantity of spatial streams, anda transmission time length that are of the cooperation STA associatedwith the second AP and that are determined by negotiation, and is usedto trigger the cooperation STA associated with the second AP to performuplink data transmission using a specified quantity of spatial streamsand a specified transmission time length, and the transmission timelength specified by the first trigger frame is the same as thetransmission time length specified by the second trigger frame.

Step S803: The cooperation STA associated with the first AP performsuplink data transmission in parallel with the cooperation STA associatedwith the second AP.

Further, after receiving the first trigger frame sent by the first AP,the cooperation STA associated with the first AP determines, based onthe delay upload indication in the first trigger frame, whether a delayupload needs to be performed.

If a delay upload indication bit in the first trigger frame indicatesthat the cooperation STA associated with the first AP needs to delayuploading, the cooperation STA associated with the first AP delays aspecified time, and after receiving the SIFS time of the second triggerframe sent by the second AP (the cooperation AP), the cooperation STAassociated with the first AP performs, using the quantity of spatialstreams and the transmission time length allocated to the first triggerframe, uplink data transmission with the cooperation STA associated withthe second AP in parallel using the quantity of spatial streams and thetransmission time length allocated to the second trigger frame.

In Embodiment 5, after the first AP and the second AP negotiate todetermine the cooperation configuration information, a schematicflowchart of triggering, by the first AP and the second AP, schedulingeach STA to perform uplink data transmission in parallel may further beshown in FIG. 10. A schematic diagram of a time sequence is shown inFIG. 11. The method may include the following steps.

Step S1001: The first AP sends a third trigger frame to the at least onecooperation STA associated with the first AP and the at least onecooperation STA associated with the second AP.

The first AP sends, in a broadcast manner based on the cooperationconfiguration information determined by negotiation in advance, thethird trigger frame to the cooperation STA associated with the first APand the cooperation STA associated with the second AP in order totrigger all the cooperation STAs associated with the first AP and thesecond AP to simultaneously perform uplink data transmission, where thethird trigger frame includes information such as an AID and a quantityof available spatial streams of the cooperation STA associated with thefirst AP, and further includes information such as an AID and a quantityof available spatial streams of the cooperation STA associated with thesecond AP. In this embodiment scenario, the first AP triggers thecooperation STA associated with the first AP and the cooperation STAassociated with the second AP to perform uplink data transmission inparallel. Therefore, the cooperation configuration information sent bythe second AP to the first AP may not include a transmission time length(PPDU length) field allocated by the second AP to the at least onecooperation STA associated with the second AP, and the first APuniformly sets the uplink transmission time length when sending thethird trigger frame.

To ensure that the first AP can accurately trigger all the cooperationSTAs associated with the first AP and the second AP, uniqueness ofassociation identifiers AID of the triggered cooperation STAs needs tobe ensured. The method for ensuring uniqueness of the AID of thecooperation STA associated with the first AP and the AID of thecooperation STA associated with the second AP may be implemented beforethe first AP and the second AP determine the cooperation information, ormay be implemented in a process in which the first AP and the second APtrigger scheduling.

Optionally, before the first AP and the second AP determine thecooperation information, it is ensured that different AIDs are allocatedby the first AP and the second AP to respective associated cooperationSTAs.

Further, the first AP and the second AP may divide the AID into two ormore non-overlapping segment intervals. The first AP and the second APmay separately allocate only the AID in a specific interval to thecooperation STA respectively associated with the first AP and the secondAP. The specific interval herein may be any two different segmentintervals, or may be any plurality of different segment intervals. Forexample, the first AP may allocate the AID to the at least onecooperation STA associated with the first AP in a first AID segmentinterval, and the second AP may allocate the AID to the at least onecooperation STA associated with the second AP in a second AID segmentinterval. The first AID segment interval does not overlap the second AIDsegment interval.

Optionally, in a process in which the first AP and the second AP triggerscheduling, AID differentiation may be implemented by including anidentifier in the trigger information.

Further, AID information in the user information field of the triggerframe includes 12 bits, where a lower 11 bits are used to indicate aspecific value of the AID, and a highest bit is a reserved bit. Forexample, as shown in Table 3, in the third trigger frame sent by thefirst AP, lower 11 bits in the AID field may be selected to representthe AID information of the cooperation STA, and a highest reserved bitin the AID field is selected as an identifier to indicate an associationBSS in which the cooperation STA is located. For example, when a highestreserved bit in the AID field is set to 0, it indicates that thecooperation STA is a STA associated with the BSS. When the reserved bitis set to 1, it indicates that the cooperation STA is not a STAassociated with the BSS. Therefore, in this case, in a process in whichthe first AP and the second AP triggers scheduling, AID information ofthe cooperation STA associated with the two APs may be distinguished,and the cooperation STA can be accurately triggered to perform uplinkdata transmission.

TABLE 3 AID 12 ID Reserved 11 bits 1 bit

Step S1002: The cooperation STA associated with the first AP and thecooperation STA associated with the second AP perform uplink datatransmission in parallel based on the quantity of spatial streamsallocated in the third trigger frame.

To ensure that the cooperation STA associated with the first AP and thecooperation STA associated with the second AP can successfully parse thetrigger scheduling information sent by the cooperation AP, beforedetermining the cooperation information, the first AP and the second APneed to notify the cooperation STA associated with the first AP and thecooperation STA associated with the second AP of a BSS color and a MACaddress of the cooperation AP in which the scheduled cooperation AP istriggered.

The cooperation STA associated with the first AP receives the thirdtrigger frame, and performs uplink data transmission in parallel withthe cooperation STA associated with the second AP based on the quantityof spatial streams and the transmission time length allocated to thecooperation STA based on the third trigger frame.

The cooperation STA associated with the second AP receives the thirdtrigger frame sent by the first AP (the cooperation AP), identifies aBSS color and a MAC address in the third trigger frame, determines thatthe third trigger frame is not another trigger frame sent by another APin the BSS, but a third trigger frame sent by a cooperation AP (thefirst AP), and performs, based on a quantity of spatial streams and atransmission time length that are allocated to the cooperation STAassociated with the second AP in the third trigger frame, uplink datatransmission in parallel with the cooperation STA associated with thefirst AP.

In Embodiment 6, after the first AP and the second AP negotiate todetermine the cooperation configuration information, a schematicflowchart of triggering, by the first AP and the second AP, schedulingeach cooperation STA to perform uplink data transmission in parallel mayfurther be shown in FIG. 12. A diagram of a time sequence is shown inFIG. 13. The method may further include the following steps.

Step S1201: The first AP and the second AP separately simultaneouslysend a fourth trigger frame to a cooperation STA in the first AP and acooperation STA in the second AP, where the fourth trigger frame is usedto trigger the cooperation STAs to perform uplink data transmission inparallel.

The first AP and the second AP separately simultaneously send, in abroadcast manner based on the cooperation configuration informationdetermined by negotiation in advance, a same fourth trigger frame to thecooperation STA associated with the first AP and the cooperation STAassociated with the second AP in order to trigger all cooperation STAsassociated with the first AP and the second AP to perform uplink datatransmission in parallel, where the fourth trigger frame includesinformation such as an AID, a quantity of available spatial streams, anda transmission time length of the cooperation STA associated with thefirst AP, and further includes information such as an AID, a quantity ofavailable spatial streams, and a transmission time length of thecooperation STA associated with the second AP, and the transmission timelength allocated to the cooperation STA associated with the first AP isthe same as the transmission time length allocated to the cooperationSTA associated with the second AP. In this embodiment, the first AP andthe second AP simultaneously send the fourth trigger frame to schedulecooperation STAs to perform uplink data transmission in parallel.Therefore, the cooperation configuration information sent by the secondAP needs to include a PPDU length field of the cooperation STAassociated with the second AP, and after receiving the cooperationconfiguration information sent by the second AP, the first AP needs toreturn cooperation acknowledgement information to the second AP. Thecooperation acknowledgement information also needs to include atransmission time length (i.e., PPDU length) field of the cooperationSTA associated with the first AP, and further needs to include allnecessary data information that facilitates the first AP and the secondAP to perform a same setting on the fourth trigger frame.

In addition, to avoid a conflict between the first AP and the fourthtrigger frame sent by the second AP, a MAC address of the fourth triggerframe needs to be set to a MAC address of either of the first AP and thesecond AP, and a scrambling code seed randomly generated for scramblingthe fourth trigger frame sent by the first AP also needs to beconsistent with that in the fourth trigger frame sent by the second APin order to ensure that the fourth trigger frame sent by the first AP iscompletely consistent with the fourth trigger frame sent by the secondAP.

As same as in the foregoing step S1001, in step S1201, to ensure thatthe first AP can accurately trigger all the cooperation STAs associatedwith the first AP and the second AP, that an associated identifier AIDof the triggered cooperation STA is unique also needs to be ensured. Inthis step, implementation of AID uniqueness is the same as thatdescribed in step S801. Details are not described herein again.

Step S1202: The cooperation STA associated with the first AP and thecooperation STA associated with the second AP perform uplink datatransmission in parallel based on the quantity of spatial streamsallocated in the fourth trigger frame.

As same as step S1002, in this step 1202, that the cooperation STAassociated with the first AP and the cooperation STA associated with thesecond AP can successfully parse the trigger scheduling information sentby the cooperation AP also needs to be ensured, before determining thecooperation information, the first AP and the second AP need to notifythe cooperation STA associated with the first AP and the cooperation STAassociated with the second AP of a BSS color and a MAC address of thecooperation AP in which the scheduled cooperation AP is triggered.

Further, the cooperation STA associated with the first AP receives thefourth trigger frame, identifies the BSS color and the MAC address inthe fourth trigger frame, and ensures that the fourth trigger frame isnot another trigger frame sent by the other AP in the BSS, but is afourth trigger frame sent by the AP (the first AP) associated with thecooperation STA or the AP (the second AP) involved in the cooperation,and performs, based on the quantity of spatial streams and thetransmission time length that are allocated to the cooperation STAassociated with the first AP based on the fourth trigger frame, uplinkdata transmission with the cooperation STA associated with the secondAP.

The cooperation STA associated with the second AP receives the fourthtrigger frame, identifies the BSS color and the MAC address in thefourth trigger frame, and ensures that the fourth trigger frame is notanother trigger frame sent by the other AP in the BSS, but is a fourthtrigger frame sent by the AP (the second AP) associated with thecooperation STA or the AP (the first AP) involved in the cooperation,and performs, based on the quantity of spatial streams and thetransmission time length that are allocated to the cooperation STAassociated with the second AP based on the fourth trigger frame, uplinkdata transmission in parallel with the cooperation STA associated withthe first AP.

Embodiment 7 provides a process in which an AP receives uplink data sentin parallel by each cooperation STA and returns to acknowledgementinformation.

In another embodiment of the present application, after each AP receivesuplink data of each cooperation STA, the method may further include,after parsing the uplink data sent by the cooperation STA associatedwith the first AP, the first AP returns acknowledgement information tothe cooperation STA associated with the first AP, and after parsing theuplink data of the cooperation STA associated with the second AP, thesecond AP returns acknowledgement information to the cooperation STAassociated with the second AP.

The first AP and the second AP have a plurality of manners of returningthe acknowledgement information.

In an optional manner, the first AP and the second AP may sequentiallyand serially return acknowledgement information to the STAs associatedwith the first AP and the second AP in terms of time. There is a timeinterval between the first AP and the second AP in terms of response theacknowledgement information. A time sequence of the first AP and thesecond AP in terms of response acknowledgement information is notlimited, and may be determined by negotiation by the first AP and thesecond AP. For example, the first AP first returns acknowledgementinformation or block acknowledgement (BA) information to the at leastone cooperation STA associated with the first AP, and then the second APreturns acknowledgement information or BA information to the cooperationSTA associated with the second AP.

In another optional manner, the first AP and the second AP add theacknowledgement information to a data field of an HE MU PPDU frame, andsend, using orthogonal frequency-division multiple access (OFDMA), theacknowledgement information to each associated STA in parallel.According to the cooperation information determined by negotiation inadvance, the first AP and the second AP perform a same setting on alegacy short training field (L-STF), a legacy long training field(L-LTF), a legacy signal field (L-SIG), an R-SIG field, anHE-SIG-Afield, and an HE signal B (HE-SIG-B) field of the HE MU PPDUframe, where a BSS color of the HE-SIG-A field in the HE MU PPDU of thefirst AP and a BSS color of the HE-SIG-A field in the HE MU PPDU of thesecond AP should be set to a same BSS color, and the BSS color may beset, after negotiation, as a BSS color of a BSS in which either of thefirst AP and the second AP is located, or may be selected as a fixed BSScolor after negotiation.

Differently, the HE-STF and HE-LTF of the HE MU PPDU of the first APcarry a resource unit allocated by the first AP to the cooperation STAassociated with the first AP, the resource unit includes atime-frequency resource allocated by the first AP to the associatedcooperation STA, and the data field includes acknowledgement informationreturned by the first AP to a corresponding associated STA. The HE-STFand the HE-LTF of the HE MU PPDU of the second AP include a resourceunit allocated by the second AP to the cooperation STA associated withthe second AP, and the data field includes acknowledgement informationreturned by the second AP to a corresponding associated STA. A frameformat of the acknowledgement information carried in the HE MU PPDU maybe shown in FIG. 14.

Optionally, as shown in FIG. 15, the first AP may further parse theuplink data sent by the cooperation STA associated with the first AP,and also parse the uplink data sent by the cooperation STA associatedwith the second AP. The first AP then returns the acknowledgementinformation to all the cooperation STAs associated with the first AP andthe second AP, and forwards the uplink data of the demodulatedcooperation STA associated with the second AP to the second AP using abackhaul or another channel or manner. A reply of the acknowledgementinformation may also be in an HE MU PPDU frame format, where the HE MUPPDU carries the acknowledgement information of the at least onecooperation STA associated with the first AP and the acknowledgementinformation of the at least one cooperation STA associated with thesecond AP.

Embodiment 8 provides a method in which an AP collaboratively performsdownlink data transmission.

After the first AP and the second AP negotiate to determine thecooperation configuration information, the first AP and the second APperform downlink data transmission to each cooperation STA in parallel,and the method may further include the following as shown in FIG. 16.

The first AP and the second AP send, based on predetermined cooperationconfiguration information, downlink data to a plurality of cooperationSTAs associated with the first AP and the second AP in parallel usingMU-MIMO using the frame format of the HE MU PPDU. Using a previousbidirectional negotiation between the first AP and the second AP, apreamble of the HE MU PPDU sent by the first AP is the same as apreamble of the HE MU PPDU sent by the second AP, a quantity of HE-LTFsin the preamble is a sum of a quantity of downlink spatial streamsallocated by the first AP and the second AP, and sequences used by eachHE-LTF are orthogonal to each other such that a cooperation STA canaccurately estimate channel information of all spatial streams and parsedownlink data corresponding to the cooperation STA. The data field ofthe HE MU PPDU sent by the first AP includes downlink data that needs tobe sent by the first AP to the at least one cooperation STA associatedwith the first AP, and the data field of the HE MU PPDU sent by thesecond AP includes downlink data that needs to be sent by the second APto the at least one cooperation STA associated with the second AP. Inthis embodiment, the first AP and the second AP simultaneously senddownlink data to each cooperation STA associated with the first AP andthe second AP. Therefore, both the cooperation configuration informationand the cooperation acknowledgement information need to include atransmission time length (i.e., PPDU length) field of the data that issent downlink by the first AP.

The cooperation STA associated with the first AP receives and parses thedownlink data sent by the first AP and return acknowledgementinformation, and the cooperation STA associated with the second APreceives the downlink data sent by the second AP and returnacknowledgement information.

The cooperation STA associated with the first AP and the cooperation STAassociated with the second AP have a plurality of manners of returningthe acknowledgement information.

Optionally, as shown in a schematic diagram 16 of a time sequence, thecooperation STA associated with the first AP and the cooperation STAassociated with the second AP may add corresponding acknowledgmentinformation to a frame format of an HE TB PPDU, and return theacknowledgment information in parallel in an OFDMA manner. When thecooperation STA associated with the first AP return the acknowledgmentinformation, an RU used in the HE TB PPDU may be indicated in the HE MUPPDU sent by the first AP, and when the cooperation STA associated withthe second AP returns the acknowledgment information, an RU used in theHE TB PPDU may be indicated in the HE TB PPDU sent by the second AP.

Optionally, the cooperation STA associated with the first AP and thecooperation STA associated with the second AP may further sequentiallyand serially return to the acknowledgement information. A sequence ofreturning the acknowledgement information by the cooperation STAassociated with the first AP and the cooperation STA associated with thesecond AP may be indicated in the HE MU PPDU sent by the first AP andthe second AP. For example, the data part of the HE MU PPDU sent by thefirst AP may be used to indicate that the cooperation STA associatedwith the first AP returns the acknowledgement information immediatelyafter receiving the downlink data, and the data part of the HE MU PPDUsent by the second AP may be used to indicate that the cooperation STAassociated with the second AP returns the acknowledgement informationafter receiving the downlink data. A specific indication sequence andmanner are not limited in this embodiment of the present application.

Embodiment 8 provides another method in which an AP collaborativelyperforms downlink data transmission.

After the first AP and the second AP negotiate to determine thecooperation configuration information, a schematic flowchart ofperforming, by the first AP and the second AP, uplink data transmissionin parallel to each cooperation STA may further be shown in FIG. 17. Adiagram of a time sequence is shown in FIG. 18. The method may furtherinclude the following steps.

Step S1701: The second AP forwards downlink data of at least onecooperation STA associated with the second AP to the first AP.

The second AP may forward, using a backhaul or another channel, the dataassociated with the second AP to the first AP.

Step S1702: The first AP sends, using the frame format of the HE MU PPDUand using a quantity of spatial streams that are correspondinglyallocated by negotiation, the downlink data to the at least onecooperation STA associated with the first AP and the at least onecooperation STA associated with the second AP.

The first AP adds the downlink data of the at least one cooperation STAassociated with the second AP and the downlink data of the cooperationSTA associated with the first AP that are forwarded by the second AP tothe HE MU PPDU, and performs downlink data transmission in a MIMOmanner. Similarly, in order that each cooperation STA can accuratelyreceive data of each cooperation STA, uniqueness of an AID of eachcooperation STA needs to be ensured. Implementation of the uniqueness ofthe AID is the same as that described in step S801. Details are notdescribed herein again. In this embodiment, the first AP sends downlinkdata to all cooperation STAs, and the transmission duration may beuniformly set by the first AP. Therefore, the cooperation configurationinformation sent by the second AP may not include the transmission timelength field of the cooperation STA associated with the second AP.

Step S1703: The first AP receives the first acknowledgement informationreturned by the at least one cooperation STA associated with the firstAP, and further receives second acknowledgement information returned bythe at least one cooperation STA associated with the second AP.

The cooperation STA associated with the first AP and the cooperation STAassociated with the second AP receive the HE MU PPDU sent by the firstAP, parse out downlink data of the cooperation STA associated with thefirst AP and the cooperation STA associated with the second AP from theHE MU PPDU, and separately return acknowledgement information to thefirst AP. Similarly, the cooperation STA associated with the first APand the cooperation STA associated with the second AP have a pluralityof manners of returning the acknowledgment information, and may returnthe acknowledgment information to the first AP in parallel using theframe format of the HE TB PPDU, or may successively return theacknowledgment information to the first AP in a serial manner. This isnot limited in the present application.

Step S1704: The first AP forwards, to the second AP, the acknowledgementinformation returned by the cooperation STA associated with the secondAP.

After receiving the acknowledgement information returned by thecooperation STA associated with the first AP and the cooperation STAassociated with the second AP, the first AP may forward, to the secondAP using the backhaul or another channel, the acknowledgementinformation returned by the cooperation STA associated with the secondAP.

Embodiment 10 provides another method in which an AP collaborativelyperforms downlink data transmission.

After the first AP and the second AP negotiate to determine thecooperation configuration information, the first AP and the second APperform downlink data transmission to each cooperation STA in parallel,and the method may further include:

After receiving the downlink data of the at least one cooperation STAassociated with the second AP that is forwarded by the second AP usingthe backhaul or another channel, the first AP forwards the downlink dataof the at least one cooperation STA associated with the first AP to thesecond AP using the backhaul or another channel.

The first AP and the second AP simultaneously send a same HE MU PPDU tothe at least one cooperation STA associated with the first AP and the atleast one cooperation STA associated with the second AP, where a datafield of the HE MU PPDU carries not only downlink data of the at leastone cooperation STA associated with the first AP, but also downlink dataof the at least one cooperation STA associated with the second AP.Further, the BSS color in the HE-SIG-A field of the HE MU PPDU may be aBSS color of any one of the first AP and the second AP, or may be afixed BSS color selected after negotiation. To ensure that eachcooperation STA can accurately identify, in the HE MU PPDU, downlinkdata sent by an associated AP to each cooperation STA, uniqueness of anAID of each cooperation STA needs to be ensured. A uniqueness assurancemethod is already described in detail in step S801. Details are notdescribed herein again. In this embodiment, because the first AP and thesecond AP need to simultaneously send the HE MU PPDU to perform downlinkdata transmission, bidirectional negotiation between the first AP andthe second AP needs to be performed. Both the cooperation configurationinformation sent by the second AP and the cooperation acknowledgementinformation returned by the first AP need to include a transmission timelength field.

An embodiment of the present application provides an apparatus 1900 fordata transmission, such as a chip complying with a series of 802.11standards or an AP. FIG. 19 is a schematic structural diagram of theapparatus 1900. The apparatus 1900 may include a configuration unit 1901configured to receive cooperation configuration information sent by asecond AP, where the cooperation configuration information of the secondAP is used to indicate basic cooperation information of the second AP tothe apparatus 1900 and a triggering unit 1902 configured to trigger,using a quantity of spatial streams allocated by the first AP to atleast one cooperation STA associated with the first AP, the at least onecooperation STA associated with the first AP to perform uplink datatransmission, where a sum of the quantity of spatial streams allocatedby the first AP to the at least one cooperation STA associated with thefirst AP and a quantity of spatial streams allocated by the second AP toat least one cooperation STA associated with the second AP does notexceed a smaller value of an upper limit of a quantity of receivedspatial streams of the first AP and an upper limit of a quantity ofreceived spatial streams of the second AP, or a sending unit 1903configured to transmit, using a quantity of spatial streams allocated bythe first AP to at least one cooperation STA associated with the firstAP, downlink data to the at least one cooperation STA associated withthe first AP, where a sum of the quantity of spatial streams allocatedby the first AP to the at least one cooperation STA associated with thefirst AP and a quantity of spatial streams allocated by the second AP toat least one cooperation STA associated with the second AP does notexceed a smallest value of upper limits of quantities of receivedspatial streams of all cooperation STAs associated with the first AP andthe second AP.

Optionally, in another embodiment of the present application, theconfiguration unit 1901 may be further configured to allocate a quantityof remaining spatial streams to the at least one cooperation STAassociated with the first AP, where the quantity of remaining spatialstreams is a quantity of remaining spatial streams that can be allocatedafter the second AP allocates the second quantity of spatial streams tothe at least one cooperation STA associated with the second AP.

Optionally, in another embodiment of the present application, theconfiguration unit 1901 may be further configured to separately allocatea quantity of spatial streams to the at least one cooperation STAassociated with the first AP and the at least one cooperation STAassociated with the second AP.

The sending unit 1903 is further configured to return cooperationacknowledgement information to the second AP, where the cooperationacknowledgement information includes at least basic cooperationinformation of the first AP.

The basic cooperation information of the first AP includes AID of acooperation STA associated with the first AP, the quantity of spatialstreams allocated by the first AP to the at least one cooperation STAassociated with the first AP, and a transmission time length.

Optionally, in another embodiment of the present application, thetriggering unit 1902 is further configured to send a first trigger frameto the at least one cooperation STA associated with the first AP, wherethe first trigger frame is used to trigger the at least one cooperationSTA associated with the first AP to perform uplink data transmissionusing a specified quantity of spatial streams and the transmission timelength after a specified delay, and the first trigger frame includes theAID of the cooperation STA associated with the first AP, the quantity ofspatial streams, the transmission time length, and a delay uplinktransmission indicator.

There is an SIFS time between the first trigger frame sent by the firstAP and a second trigger frame sent by the second AP, the second triggerframe is used to trigger the at least one cooperation STA associatedwith the second AP to perform uplink data transmission using a specifiedquantity of spatial streams and a transmission time length, and thetransmission time length of the at least one cooperation STA associatedwith the first AP is the same as that of the at least one cooperationSTA associated with the second AP.

Optionally, the triggering unit 1902 may be further configured to send athird trigger frame to the at least one cooperation STA associated withthe first AP and the at least one cooperation STA associated with thesecond AP, where the third trigger frame is used to trigger the at leastone cooperation STA associated with the first AP and the at least onecooperation STA associated with the second AP to perform uplink datatransmission in parallel using a corresponding specified quantity ofspatial streams.

The third trigger frame includes an AID of the at least one cooperationSTA associated with the first AP, a quantity of available spatialstreams of the at least one cooperation STA associated with the firstAP, and an AID of the at least one cooperation STA associated with thesecond AP, and a quantity of available spatial streams of the at leastone cooperation STA associated with the second AP.

Optionally, in another embodiment, the triggering unit 1902 is furtherconfigured to trigger the second AP to simultaneously send a fourthtrigger frame to the at least one cooperation STA associated with thefirst AP and the at least one cooperation STA associated with the secondAP, where the fourth trigger frame is used to trigger the at least onecooperation STA associated with the first AP and the at least onecooperation STA associated with the second AP to perform uplink datatransmission in parallel using a corresponding specified quantity ofspatial streams.

The fourth trigger frame includes an AID of the at least one cooperationSTA associated with the first AP, a quantity of available spatialstreams of the at least one cooperation STA associated with the firstAP, an AID of the at least one cooperation STA associated with thesecond AP, and a quantity of available spatial streams of the at leastone cooperation STA associated with the second AP.

A MAC address of the fourth trigger frame is a MAC address of either ofthe first AP and the second AP, or is a common MAC address of the firstAP and the second AP.

Optionally, in another embodiment of the present application, theapparatus 1900 further includes a receiving unit 1904 configured toreceive and parse uplink data sent by the at least one cooperation STAassociated with the first AP, and the sending unit 1903 is furtherconfigured to return, simultaneously with the second AP in an HE MU PPDUframe format, acknowledgement information to the at least onecooperation STA associated with the first AP and the at least onecooperation STA associated with the second AP, where a preamble of an HEMU PPDU sent by the first AP and a preamble of an HE MU PPDU sent by thesecond AP have same fields different from HE-STF and HE-LTFs, and a BSScolor in the HE MU PPDU sent by the first AP is the same as a BSS colorin the HE MU PPDU sent by the second AP, or the sending unit 1903 isfurther configured to return, simultaneously with the second AP,acknowledgement information in series in a time division manner to atleast one cooperation STA associated with the APs.

Optionally, in another embodiment of the present application, thereceiving unit 1904 is further configured to receive and parse uplinkdata sent by the at least one cooperation STA associated with the firstAP and the at least one cooperation STA associated with the second AP.

The sending unit 1903 is further configured to return theacknowledgement information to the at least one cooperation STAassociated with the first AP and the at least one cooperation STAassociated with the second AP.

The sending unit 1903 is further configured to forward the uplink dataof the at least one cooperation STA associated with the second AP to thesecond AP.

Optionally, the sending unit 1903 is further configured to separatelysend, simultaneously with the second AP in an HE MU PPDU frame formatusing a specified quantity of transmit streams, downlink data to the atleast one cooperation STA associated with the first AP and the at leastone cooperation STA associated with the second AP.

A preamble of an HE MU PPDU sent by the first AP is the same as apreamble of an HE MU PPDU sent by the second AP, a quantity of HE-LTFsin the preambles is a total quantity of spatial streams allocated by thefirst AP and the second AP, and sequences used by all the HE-LTFs aremutually orthogonal.

Optionally, in another embodiment of the present application, thereceiving unit 1904 is further configured to receive firstacknowledgement information returned by the at least one cooperation STAassociated with the first AP, and the second AP receives secondacknowledgement information returned by the at least one cooperation STAassociated with the second AP.

The first acknowledgement information and the second acknowledgementinformation are sent in series by the at least one cooperation STAassociated with the first AP and the at least one cooperation STAassociated with the second AP, or the first acknowledgement informationand the second acknowledgement information are sent in parallel in an HETB PPDU format by the at least one cooperation STA associated with thefirst AP and the at least one cooperation STA associated with the secondAP.

Optionally, the receiving unit 1904 is further configured to receivefirst acknowledgement information returned by the at least onecooperation STA associated with the first AP, and further receive secondacknowledgement information returned by the at least one cooperation STAassociated with the second AP.

The sending unit 1903 is further configured to forward the secondacknowledgement information of the at least one cooperation STAassociated with the second AP to the second AP.

For a working principle of the foregoing data transmission apparatus1900, refer to FIG. 2 to FIG. 17 and corresponding method descriptions.Details are not described herein again.

Referring to FIG. 20, an embodiment of the present application providesan apparatus 2000 for data transmission. The apparatus 2000 includes asending unit 2002 configured to perform, based on a quantity of spatialstreams allocated by the first AP, uplink data transmission in parallelwith at least one cooperation STA associated with a second AP, where asum of the quantity of spatial streams allocated by the first AP to atleast one cooperation STA associated with the first AP and a quantity ofspatial streams allocated by the second AP to the at least onecooperation STA associated with the second AP does not exceed a smallervalue of an upper limit of a quantity of received spatial streams of thefirst AP and an upper limit of a quantity of received spatial streams ofthe second AP, or a receiving unit 2001 configured to receive, based onthe quantity of spatial streams allocated by the first AP, downlink datasent by the first AP, where a sum of the quantity of spatial streamsallocated by the first AP to the at least one cooperation STA associatedwith the first AP and a quantity of spatial streams allocated by thesecond AP to the at least one cooperation STA associated with the secondAP does not exceed a smallest value of upper limits of quantities ofreceived spatial streams of all cooperation STAs associated with thefirst AP and the second AP.

Optionally, in another embodiment of the present application, thereceiving unit 2001 is further configured to receive a first triggerframe sent by the first AP, where the first trigger frame is used totrigger the at least one cooperation STA associated with the first AP toperform uplink data transmission using a specified quantity of spatialstreams after a specified delay.

The sending unit 2002 is further configured to perform, based on a delayupload indication of the first trigger frame, uplink data transmissionin parallel with the at least one cooperation STA associated with thesecond AP after receiving a second trigger frame sent by the second APand there is an SIFS time between the first trigger frame sent by thefirst AP and a second trigger frame sent by the second AP, the secondtrigger frame is used to trigger the at least one cooperation STAassociated with the second AP to perform uplink data transmission usinga specified quantity of spatial streams, and the transmission timelength of the at least one cooperation STA associated with the first APis the same as that of the at least one cooperation STA associated withthe second AP.

Optionally, in another embodiment of the present application, thereceiving unit 2001 is further configured to receive, together with acooperation STA associated with the second AP, a third trigger framesent by the first AP, where the third trigger frame is used to triggerthe at least one cooperation STA associated with the first AP and the atleast one cooperation STA associated with the second AP to performuplink data transmission in parallel using each corresponding specifiedquantity of spatial streams.

The sending unit 2002 is further configured to perform, together with acooperation STA associated with the second AP, uplink data transmissionin parallel based on a quantity of spatial streams that arecorrespondingly allocated in the third trigger frame, and the thirdtrigger frame includes an AID of the at least one cooperation STAassociated with the first AP, a quantity of available spatial streams ofthe at least one cooperation STA associated with the first AP, and anAID of the at least one cooperation STA associated with the second AP,and a quantity of available spatial streams of the at least onecooperation STA associated with the second AP.

Optionally, in another embodiment of the present application, thereceiving unit 2001 is further configured to receive, together with acooperation STA associated with the second AP, a fourth trigger framesent by the first AP and a fourth trigger frame sent by the second AP,where the third trigger frame is used to trigger the at least onecooperation STA associated with the first AP and the at least onecooperation STA associated with the second AP to perform uplink datatransmission in parallel using each corresponding specified quantity ofspatial streams.

The sending unit 2002 is further configured to perform, together withthe cooperation STA associated with the second AP, uplink datatransmission in parallel based on a quantity of spatial streams that arecorrespondingly allocated in the fourth trigger frame, and a MAC addressof the fourth trigger frame is a MAC address of either of the first APand the second AP, or is a common MAC address of the first AP and thesecond AP.

Further, optionally, the sending unit 2002 is further configured tosequentially and serially return first acknowledgement information andsecond acknowledgement information together with the at least onecooperation STA associated with the second AP, or the sending unit 2002is further configured to return the first acknowledgement informationand the second acknowledgement information in parallel together with theat least one cooperation STA associated with the second AP using a frameformat of an HE TB PPDU.

For a working principle of the foregoing data transmission apparatus2000, refer to FIG. 2, FIG. 8 to FIG. 17 and corresponding methoddescriptions. Details are not described herein again.

FIG. 21 shows an AP apparatus 2100 according to an embodiment of thepresent application.

The apparatus 2100 includes a transceiver 2101, a processor 2102, and amemory 2103. The transceiver 2101, the processor 2102, and the memory2103 are interconnected. A specific medium for connecting the foregoingparts is not limited in this embodiment of the present application. Inthis embodiment of the present application, in FIG. 21, the memory 2103,the processor 2102, and the transceiver 2101 are connected using a bus2104, and the bus 2104 is represented by a bold line in FIG. 21. Aconnection manner between other parts is merely an example fordescription, and does not impose a limitation. Based on constraints onspecific application and overall design of the AP apparatus 2100, thebus 2104 may include any quantity of interconnected buses and bridges.The bus 2104 may be classified into an address bus, a data bus, acontrol bus, and the like. For ease of representation, only one thickline is used to represent the bus 2104 in FIG. 21, but this does notmean that there is only one bus or only one type of bus.

The memory 2103 may include a read-only memory (ROM) and a random accessmemory (RAM), and provide an instruction and data to the processor 2102.A part of the memory 2103 may further include a non-volatile RAM(NVRAM). For example, the memory 2103 may further store informationabout an apparatus type. The processor 2102 may be configured to executethe instruction stored in the memory 2103, and when the processor 2102executes the instruction, the processor 2102 may perform steps in theforegoing method embodiments in FIG. 2 to FIG. 15 and methoddescriptions corresponding to the method embodiments.

FIG. 22 shows a STA apparatus 2200 according to an embodiment of thepresent application.

The STA apparatus 2200 includes a transceiver 2201, a processor 2202,and a memory 2203. The transceiver 2201, the processor 2202, and thememory 2203 are interconnected. A specific medium for connecting theforegoing parts is not limited in this embodiment of the presentapplication. In this embodiment of the present application, in FIG. 22,the memory 2203, the processor 2202, and the transceiver 2201 areconnected using a bus 2204, and the bus 2204 is represented by a boldline in FIG. 22. A connection manner between other parts is merely anexample for description, and does not impose a limitation. Based onconstraints on specific application and overall design of the STAapparatus 2200, the bus 2204 may include any quantity of interconnectedbuses and bridges. The bus 2204 may be classified into an address bus, adata bus, a control bus, and the like. For ease of representation, onlyone thick line is used to represent the bus 2204 in FIG. 22, but thisdoes not mean that there is only one bus or only one type of bus.

Optionally, the memory 2203 includes a ROM and a RAM, and provides aninstruction and data to the processor 2202. A part of the memory 2203may further include an NVRAM. For example, the memory 2203 may furtherstore information about an apparatus type, but is not limited herein.The processor 2202 may be configured to execute the instruction storedin the memory 2203, and the processor 2202 may perform stepscorresponding to the apparatus in the foregoing method embodiment.

It should be noted that a person skilled in the art may understand thatdivision of modules in the embodiments is an example, and is merelylogical function division. There may be another division manner inactual implementation. In addition, functional modules in theembodiments of this application may be integrated into one processingmodule, or each module may exist alone physically, or two or moremodules are integrated into one module. The integrated module may beimplemented in a form of hardware, or may be implemented in a form of asoftware functional module. In addition, there may be a plurality ofspecific naming manners of concepts and apparatus function modules inthe foregoing embodiments. For example, in addition to being referred toas an AP, the AP may also be referred to as a base STA, a router, agateway, a repeater, or a bridge. In addition to being referred to as aSTA, the STA may also be referred to as a terminal, a user apparatus, orthe like. This is not limited in the present application.

A person skilled in the art should understand that the embodiments ofthe present application may be provided as a method, a system, or acomputer program product. Therefore, the present application may use aform of hardware only embodiments, software only embodiments, orembodiments with a combination of software and hardware. In addition, acomputer readable storage medium may be further used in the presentapplication, and the computer readable storage medium stores aninstruction. When the instruction is run on a computer, the computer isenabled to perform the method in the foregoing aspects. According tostill another aspect, an embodiment of the present application providesa computer program product including an instruction. When the computerprogram product is run on a computer, the computer is enabled to performthe method in the foregoing aspects.

The foregoing descriptions are merely optional embodiments of thepresent application, but are not intended to limit the presentapplication. Any variation or replacement readily figured out by aperson skilled in the art within the technical scope disclosed in thepresent application shall fall within the protection scope of thepresent application. Therefore, the protection scope of the presentapplication shall be subject to the protection scope of the claims.

1. A data transmission method implemented by a first access point (AP),comprising: generating a first trigger frame; and sending the firsttrigger frame to a first cooperation station (STA) associated with thefirst AP, wherein the first trigger frame comprises a first associationidentifier (AID) of the first cooperation STA, a first quantity ofspatial streams, and a first transmission time length, wherein the firsttrigger frame triggers the first cooperation STA to perform first uplinkdata transmission, wherein there is a short interframe space (SIFS) timebetween when the first AP sends the first trigger frame and when asecond AP sends a second trigger frame and wherein the firsttransmission time length is the same as a second transmission timelength of a second cooperation STA associated with the second AP.
 2. Thedata transmission method of claim 1, wherein the first trigger framefurther comprises a delay uplink transmission indicator, and wherein thedelay uplink transmission indicator instructs the first cooperation STAto perform the first uplink data transmission after a first delay. 3.The data transmission method of claim 2, wherein the delay uplinktransmission indicator is a reserve bit is a common information field ofthe first trigger frame.
 4. The data transmission method of claim 1,wherein a sum of the first quantity of spatial streams and a secondquantity of spatial streams allocated by the second AP to the secondcooperation STA does not exceed a minimum value of upper limits ofquantities of received spatial streams of all cooperation STAsassociated with the first AP and the second AP.
 5. The data transmissionmethod of claim 1, wherein before sending the first trigger frame to thefirst cooperation STA, the data transmission method further comprisesreceiving cooperation configuration information from the second AP, andwherein the cooperation configuration information comprises a second AIDof the cooperation.
 6. The data transmission method of claim 5, whereinthe cooperation configuration information further comprises a quantityof cooperation STAs associated with the second AP, a modulation andcoding scheme, and the second transmission time length.
 7. A datatransmission apparatus applied in a first access point (AP), comprising:a processor, and a memory coupled to the processor and configured tostore instructions that, when executed by the processor, cause the datatransmission apparatus to: generate a first trigger frame; and send thefirst trigger frame to a first cooperation station (STA) associated withthe first AP, wherein the first trigger frame comprises a firstassociation identifier (AID) of the first cooperation STA, a firstquantity of spatial streams, and a first transmission time length,wherein the first trigger frame triggers the first cooperation STA toperform first uplink data transmission, wherein there is a shortinterframe space (SIFS) time between when the first AP sends the firsttrigger frame and when a second AP sends a second trigger frame andwherein the first transmission time length is the same as a secondtransmission time length of a second cooperation STA associated with thesecond AP.
 8. The data transmission apparatus of claim 7, wherein thefirst trigger frame further comprises a delay uplink transmissionindicator, and wherein the delay uplink transmission indicator instructsthe first cooperation STA to perform the first uplink data transmissionafter a first delay.
 9. The data transmission apparatus of claim 8,wherein the delay uplink transmission indicator is a reserve bit in acommon information field of the first trigger frame.
 10. The datatransmission apparatus of claim 7, wherein a sum of the first quantityof spatial streams and a second quantity of spatial streams allocated bythe second AP to the second cooperation STA does not exceed a minimumvalue of upper limits of quantities of received spatial streams of allcooperation STAs associated with the first AP and the second AP.
 11. Thedata transmission apparatus of claim 7, wherein the instructions that,when executed by the processor, further cause the data transmissionapparatus to receive, cooperation configuration information from thesecond AP, and wherein the cooperation configuration informationcomprises at least one of a second AID of the cooperation STA or asecond quantity of spatial streams of the second cooperation STA. 12.The data transmission apparatus of claim 11, wherein the cooperationconfiguration information further comprises a quantity of cooperationSTAs associated with the second AP, a modulation and coding scheme, andthe second transmission time length.
 13. A first cooperation station(STA), comprising: a processor, and a memory coupled to the professorand configured to store instructions that, when executed by theprocessor, cause the first cooperation STA to: receive a first triggerframe from a first access point (AP) associated with the cooperationSTA, wherein the first trigger frame comprises a first associationidentifier (AID) of the first cooperation STA, a first quantity ofspatial streams, and a first transmission time length wherein the firsttrigger frame instructs to trigger the first cooperation STA to performfirst uplink data transmission, wherein there is a short interframespace (SIFS) time between when the first AP sends the first triggerframe and when a second AP sends a second trigger frame and wherein thefirst transmission time length is the same as a second transmission timelength of cooperation STA associated with the second AP; and perform thefirst uplink data transmission based on the first trigger frame.
 14. Thefirst cooperation STA of claim 13, wherein the first trigger framefurther comprises a delay uplink transmission indicator, wherein thedelay uplink transmission indicator instructs the first cooperation STAto perform the first uplink data transmission after a first delay, andwherein the instructions that, when executed by the processor, furthercause first cooperation STA to perform the first uplink datatransmission after the first delay.
 15. The first cooperation STA ofclaim 14, wherein the delay uplink transmission indicator is a reservebit in a common information field of the first trigger frame.
 16. Thefirst cooperation STA of claim 14, wherein the delay uplink transmissionindicator is a reserve bit in a user info field of the first triggerframe.
 17. The data transmission method of claim 2, wherein the delayuplink transmission indicator is a reserve bit in a user info field ofthe first trigger frame.
 18. The data transmission method of claim 1,wherein before sending the first trigger frame to the first cooperationSTA, the data transmission method further comprises receivingcooperation configuration information from the second AP, and whereinthe cooperation configuration information comprises a second quantity ofspatial streams of the second cooperation STA, a quantity of cooperationSTAs associated with the second AP, a modulation and coding scheme, andthe second transmission time length.
 19. The data transmission method ofclaim 1, wherein before sending the first trigger frame to the firstcooperation STA, the data transmission method further comprisesreceiving cooperation configuration information from the second AP, andwherein the cooperation configuration information comprises a second AIDof the second cooperation STA, a second quantity of spatial streams ofthe second cooperation STA, a quantity of cooperation STAs associatedwith the second AP, a modulation and coding scheme, and the secondtransmission time length.
 20. The data transmission apparatus of claim8, wherein the delay uplink transmission indicator is a reserve bit in auser info field of the first trigger frame.